These studies are designed to explore the role of cell surface lectin-carbohydrate interactions in cellular recognition, cooperation, and regulation. Special emphasis is placed on the role of complex carbohydrates and glycoproteins in the regulation of immune response during human pregnancy. A mannose 1-6 dimer of mannose and a more complex glycoprotein have been purified from human pregnancy urine. The glycoprotein which we term uromodulin appears to specifically inhibit the action of interleukin-1. We are undertaking studies to examine the mechanism of this inhibition and the clinical significance of circulating uromodulin.